There exists a control device for a steering apparatus such as a power steering apparatus which has an assist mode in which, based on the driving condition of the vehicle, controls an actuator equipped with a motor, etc. to impart a steering auxiliary force to the steering force of the driver, and an automatic steering mode in which a target steering angle is generated based on a command value of a host controller and in which the actuator is controlled to automatically adjust a turning wheel steering angle. In an example of such a steering apparatus, switching is effected from the automatic steering to the assist when the steering torque of the driver detected by a torque sensor during automatic steering has attained a predetermined value (threshold value) or more (see, for example, Patent Document 1 below).
Further, there is a steering apparatus in which, in order to suppress the steering wheel vibration during automatic steering, a twist angle generated in a torsion bar is detected and in which the electric current command value of a motor is calculated based on the twist angle and a twist angle differential value to control the motor (see, for example, Patent Document 2 below).
Further, there has been proposed a steering apparatus in which a target steering angle is corrected such that the angular acceleration of the target steering angle during automatic steering is a limitation value or less and in which, based on information on the turning angle, the motor is controlled such that the turning angle is in conformity with the corrected target steering angle (see, for example, Patent Document 3 below).